Castles were also developed to defend key part of the countryside such as a mountain pass or river estuary, and often made use of the natural geography to support the defensive walls through exploitation of cliffs, rivers, hills, and the like.
Warwick Castle Warwick Castle lies in the town of Warwick in the county of Warwickshire in central England and overlooks the River Avon.
Windsor Castle Windsor Castle is, along with Buckingham Palace in London and Holyrood Palace in Edinburgh, one of the principal official residences of the British monarch.